Signal recognition particle receptor exposes the ribosomal translocon binding site     

Halic M  Gartmann M  Schlenker O  Mielke T  Pool MR  Sinning I  Beckmann R 《Science (New York, N.Y.)》2006,312(5774):745-747

Signal sequences of secretory and membrane proteins are recognized by the signal recognition particle (SRP) as they emerge from the ribosome. This results in their targeting to the membrane by docking with the SRP receptor, which facilitates transfer of the ribosome to the translocon. Here, we present the 8 angstrom cryo-electron microscopy structure of a "docking complex" consisting of a SRP-bound 80S ribosome and the SRP receptor. Interaction of the SRP receptor with both SRP and the ribosome rearranged the S domain of SRP such that a ribosomal binding site for the translocon, the L23e/L35 site, became exposed, whereas Alu domain-mediated elongation arrest persisted.  相似文献   

Optimized LC/MS/MS analysis of morphine and codeine in poppy seed and evaluation of their fate during food processing as a basis for risk analysis     

Sproll C  Perz RC  Lachenmeier DW 《Journal of agricultural and food chemistry》2006,54(15):5292-5298

The opiate alkaloids present in poppy seed intended for use in food recently have raised major concerns. An efficient method for routine analysis of morphine and codeine using liquid chromatography in combination with tandem mass spectrometry on a triple quadrupole instrument (LC/MS/MS) was therefore developed. The optimal sample preparation was found to be cold extraction of 10 g of unground poppy seed with 30 mL of methanol containing 0.1% acetic acid for 60 min shaken at 250 rpm. The fate of morphine during food processing was also studied. All experiments led to a significant reduction of morphine and codeine. For poppy cake only 16-50% of the morphine was recovered, and in poppy buns at the highest temperature (220 degrees C) only 3% of the original morphine content was found. Ground poppy seed showed significantly lower recoveries than untreated seed. Morphine elimination during food processing has to be taken into account in the current discussion about its maximum limits in poppy seed.  相似文献   

New strategies for the elimination of polio from India     

Grassly NC  Fraser C  Wenger J  Deshpande JM  Sutter RW  Heymann DL  Aylward RB 《Science (New York, N.Y.)》2006,314(5802):1150-1153

The feasibility of global polio eradication is being questioned as a result of continued transmission in a few localities that act as sources for outbreaks elsewhere. Perhaps the greatest challenge is in India, where transmission has persisted in Uttar Pradesh and Bihar despite high coverage with multiple doses of vaccine. We estimate key parameters governing the seasonal epidemics in these areas and show that high population density and poor sanitation cause persistence by not only facilitating transmission of poliovirus but also severely compromising the efficacy of the trivalent vaccine. We analyze strategies to counteract this and show that switching to monovalent vaccine may finally interrupt virus transmission.  相似文献   

Difficulties for foreign scientists in coming to the United States     

D'Elia CF  Bradley G  Schmitt R 《Science (New York, N.Y.)》2006,313(5784):169

  相似文献   

ECG of the month. Ventricular preexcitation     

Roland RM  Estrada AH 《Journal of the American Veterinary Medical Association》2006,228(10):1500-1502

  相似文献   

Energy capture from thermolytic solutions in microbial reverse-electrodialysis cells     

Cusick RD  Kim Y  Logan BE 《Science (New York, N.Y.)》2012,335(6075):1474-1477

Reverse electrodialysis allows for the capture of energy from salinity gradients between salt and fresh waters, but potential applications are currently limited to coastal areas and the need for a large number of membrane pairs. Using salt solutions that could be continuously regenerated with waste heat (≥40°C) and conventional technologies would allow much wider applications of salinity-gradient power production. We used reverse electrodialysis ion-exchange membrane stacks in microbial reverse-electrodialysis cells to efficiently capture salinity-gradient energy from ammonium bicarbonate salt solutions. The maximum power density using acetate reached 5.6 watts per square meter of cathode surface area, which was five times that produced without the dialysis stack, and 3.0 ± 0.05 watts per square meter with domestic wastewater. Maximum energy recovery with acetate reached 30 ± 0.5%.  相似文献   

Metabolite profiling identifies a key role for glycine in rapid cancer cell proliferation     

Jain M  Nilsson R  Sharma S  Madhusudhan N  Kitami T  Souza AL  Kafri R  Kirschner MW  Clish CB  Mootha VK 《Science (New York, N.Y.)》2012,336(6084):1040-1044

Metabolic reprogramming has been proposed to be a hallmark of cancer, yet a systematic characterization of the metabolic pathways active in transformed cells is currently lacking. Using mass spectrometry, we measured the consumption and release (CORE) profiles of 219 metabolites from media across the NCI-60 cancer cell lines, and integrated these data with a preexisting atlas of gene expression. This analysis identified glycine consumption and expression of the mitochondrial glycine biosynthetic pathway as strongly correlated with rates of proliferation across cancer cells. Antagonizing glycine uptake and its mitochondrial biosynthesis preferentially impaired rapidly proliferating cells. Moreover, higher expression of this pathway was associated with greater mortality in breast cancer patients. Increased reliance on glycine may represent a metabolic vulnerability for selectively targeting rapid cancer cell proliferation.  相似文献   

Electroporation improves the immune response induced by a DNA vaccine against pseudorabies virus glycoprotein B in pigs     

Le Moigne V  Cariolet R  Béven V  Keranflec'h A  Jestin A  Dory D 《Research in veterinary science》2012,93(2):1032-1035

This study was performed to determine whether electroporation can be used to enhance the efficacy of a DNA vaccine against pseudorabies virus (PrV) in pigs. Immune responses to PrV were measured in pigs following a single intramuscular injection of plasmids encoding PrV glycoprotein B, with or without electroporation. Plasmid injection coupled with electroporation increased production of specific antibodies against PrV and peripheral blood mononuclear cells proliferated in response to stimulation with PrV glycoproteins. These results show that electroporation can improve the performance of a DNA vaccine against PrV in pigs. However, additional work is required to maximise the effectiveness of the vaccination protocol.  相似文献   

Potential application of serological tests on fluids from carcasses: detection of antibodies against Toxoplasma gondii and Sarcoptes scabiei in red foxes (Vulpes vulpes)     

Eva-Britt Jakubek  Roland Mattsson  Torsten M?rner  Jens G Mattsson  Dolores Gavier-Widén 《Acta veterinaria Scandinavica》2012,54(1):13

Background

Serological surveys for disease investigation of wild animal populations require obtaining blood samples for analysis, which has logistic, ethic and economic difficulties. Applying serological test to fluids collected from dead animals is an alternative. The aim of this study was to assess if antibodies could be detected in two types of fluids collected from 56 carcasses of red foxes (Vulpes vulpes): pleural fluid and lung extract.

Findings

In 22 (39%) foxes antibodies against Sarcoptes scabiei were detected in both fluid types by ELISA and Western blot. In 46 (82%) foxes, antibodies against Toxoplasma gondii were detected in pleural fluid and in 41 (73%) in lung extract applying a Toxo-screen test (DAT). Antibodies were still detectable in the same fluids kept at room temperature for 28 days, although in fewer foxes (16 and 14 foxes tested for T. gondii in lung extract and pleural fluid respectively; and 1 and 4 tested for S. scabiei in lung extract and pleural fluid respectively.

Conclusions

These results indicate the potential utility of using fluids from carcasses for antibody screening of wild animals at the population level.  相似文献   

Greenhouse gas emissions from Silphium perfoliatum and silage maize cropping on Stagnosols     

Björn Kemmann  Thorsten Ruf  Reinhard Well  Christoph Emmerling  Roland Fuß 《植物养料与土壤学杂志》2023,186(1):79-94

Background

The sustainability of bioenergy is strongly affected by direct field-derived greenhouse gas (GHG) emissions and indirect emissions form land-use change. Marginal land in low mountain ranges is suitable for feedstock production due to small impact on indirect land-use change. However, these sites are vulnerable to high N₂O emissions because of their fine soil texture and hydrology.

Aims

The perennial cup plant (Silphium perfoliatum L.) might outperform silage maize (Zea mays L.) on cold, wet low mountain ranges sites regarding yield and ecosystem services. The aim of this study was to assess whether the cultivation of cup plant also provides GHG mitigation potential compared to the cultivation of maize.

Methods

A t-year field experiment was conducted in a low mountain range region in western Germany to compare area and yield-scaled GHG emissions from cup plant and maize fields. GHG emissions were quantified using the closed chamber method.

Results

Cup plant fields emitted an average of 3.6 ± 4.3 kg N₂O-N ha^–1 year^–1 (–85%) less than maize fields. This corresponded to 74.0 ± 94.1 g CO_2-eq kWh^–1 (–78%) less emissions per produced electrical power. However, cup plant had a significantly lower productivity per hectare (–34%) and per unit of applied nitrogen (–32%) than maize.

Conclusion

Cup plant as a feedstock reduces direct field-derived GHG emissions compared to maize but, due to lower yields cup plant, likely increases emissions associated with land-use changes. Therefore, the increased sustainability of bioenergy from biogas by replacing maize with cup plant is heavily dependent on the performance of maize at these sites and on the ecosystem services of cup plant in addition to GHG savings.  相似文献